.window-frame, .window-frame:backdrop {
 box-shadow: 0 0 0 black;
 border-style: none;
 margin: 0;
 border-radius: 0;
}

.titlebar {
 border-radius: 0;
}

.window-frame.csd.popup {
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.2), 0 0 0 1px rgba(0, 0, 0, 0.13);
}

.header-bar {
  background-image: none;
  background-color: #ededed;
  box-shadow: none;
}
/* You may want to use this if you do not like the double title.
GtkLabel.title {
    opacity: 0;
}*/